A prior art electrical connector is shown in FIG. 4, which comprises a plug connector 1 having a plug housing 2 which receives and retains a plurality of receptacle contacts 3 to which end portions of wires 9 are connected, and a cap connector 5 having a cap housing 6 which receives and retains a plurality of plug contacts 7 to which end portions of wires 9 are connected. To connect the connectors 1 and 5, a front end 2a of the plug housing 2 is inserted in a cavity 6a of the cap housing 6, and front ends 7a of the plug contacts 7, which project inside the cavity 6a, are electrically connected with respective receptacle contacts 3. Thus, an electrical connection between the contacts 3 and 7 is made.
In this case, when the contact sections or front ends 7a of the plug contacts 7 are misaligned in the vertical or lateral direction, the front ends 7a of the plug contacts 7 cannot be properly mated with the receptacle contacts 3. Accordingly, although the front end 2a of the plug housing 2 is inserted in the cavity 6a, the front ends 7a of the plug contacts 7a are not correctly aligned with the receptacle contacts 3, therefore a problem of an incomplete electrical connection between the contacts 3 and 7 occurs.
To prevent such an incomplete connection, a position alignment gauge was used to position the front ends of the plug contacts in alignment with the receptacle contacts after fitting the plug contact in the cap housing. However, this meant that the position alignment gauge had to be used on all of the cap connectors which slowed the assembly operation in addition to increasing the cost of the connectors.